Time for a new engine? 2010 320i E91

[northwest monkey]

Hi all, could do with some advice.

I have a 320i E91 M Sport Business blah blah. It's a 2010 LCI model with 106k miles.

Not long after buying it, I had a couple of issues with it.

Firstly, during a run on the motorway, it came up with an "Oil Pressure Low" warning - I immediately pulled over, stopped the engine, waited a bit & restarted it though and this warning did not come back. I checked the oil level (via the I-Drive) and it was perfect. There are no signs of any oil burning (blue smoke, wet exhaust etc.) and there don't appear to be any leaks in the engine bay or any oil on my drive.

It was also "ticking" a lot from seemingly the top of the engine and I was getting an EML (only once a day bizarrely) so I took it to a neighbours garage where he plugged it into his Autologic machine.

It came up with the following fault codes:-

29F3 - Fuel low-pressure sensor, electric
30C1 - Engine oil pressure control, static
2A99 - Crankshaft - exhaust camshaft, reference
30DA - Nitrogen-oxide sensor, signal
2AF4 - Nitrogen-oxide sensor, electric
2AF2 - Nitrogen-oxide sensor, lambda linear
2AF6 - Nitrogen-oxide sensor, lambda binary
2AF9 - Nitrogen-oxide sensor, NOX signal, coast-mode check

It also checked (using some sort of voodoo presumably) that the car needed 9 updates.

So, the neighbour recommended to start with an oil flush & new oil/filter and the updates doing. He also advised a new oil filler cap as the seals can perish slightly. So, all that has been done & to be honest, the car does seem an awful lot better - much smoother. It does have service history, but in 106k miles, has only seen a garage 6 times which is pretty shocking (stupid CBS).

After doing the oil change, the codes were cleared & rescanned & the only ones that have returned are the "NOX" ones (which I can live with).

The "ticking" seems better - , however I am still getting the "Oil Pressure Low" warning, but only when I've been on the motorway (and not every time). What I do have is a what I can only describe as a "rumbling" or slight knocking from the engine but not all the time. If the car is idling, it isn't there, if the car is driving, it isn't there (or I can't hear it), it's if I rev the engine then when the revs are coming down I can hear it, or when I change gear (and the revs drop).

When I start it up from cold in the morning, it does sound rough for (at max) a couple of seconds then quietens down. It does sometimes run rough though but if I stop it & start it again it runs fine.

So, any ideas as to what this could be and any recommendations for a BMW specialist in the East Lancs area?

Really need this sorted pretty quick as I'm off to France in August and definitely don't want to be returning home on a flatbed with the Mrs, our son and the MiL...

Being the internet, I've read everything from "ignore it" to "you're going to explode and it will bum your dog" and being honest, I'm now worrying slightly (not about the dog).

I did buy the car from a Ltd Co. home trader and I am aware of "my rights" etc, but I'm also aware that being a 6-year old car with 100k miles on isn't going to be perfect and any warranty company is going to squirm like mad to not pay out. I have spoken to the lad I bought it off & to be fair he's paid the £150 for the Autologic check, the oil change & for the updates to be done. I haven't spoken him since though (other than to thank him for paying for it).

I know these engines have a reputation, but then again pretty much every engine does if you read the internet. FWIW I had an MG6 with the turbocharged K-series engine in for over 2 years & never had a problem.

There is a garage relatively local to me that will supply & fit a "new" engine for under £1400 which seems reasonable (to me it does anyway - I haven't mentioned this to the Mrs)

Cheers for reading & apologies for waffling on, Dave

TL: DR - car making a funny noise and getting "low oil pressure".

[Elliot2000]

Is it a red light or yellow oil pressure light?

These engines have variable oil pressure control and the mechanisms and electric valves can both cause issues.

If the yellow light comes on the valve should default to max pressure anyway so hopefully it shouldn't cause any damage

[gf15]

I had a failed (erratic) oil level sensor. Warning cam on to add a litre of oil. I added a 1/4 litre of oil and the oil level sensor went back to 5 green bars. If you have a dip stick, I would use that. Good luck.

[northwest monkey]

Sadly I haven't got a dipstick - it's the electronic one on the I-Drive thing.

It wasn't the "oil level" light that came on, it was definitely "low oil pressure" & I'm not 100% but I think it was red. It came up on the display behind the steering wheel and on the I-drive screen.

Normal day to day driving the light doesn't come on but the noise is there.

[CarsOrBikes]

That and the rumble, worse when warm hints at bearing wear to me, mains rumble, ends knock, mains affect pressure... worse with temp, it may have been run low on oil a few times in it's 106k, that and the minimum required change interval which everyone relies on, is too much for oil that's worked harder at a potentially low level, accelerating wear. Only my2p and hopefully not that, the crank can be in poor shape, but you may improve it a lot by just getting new shells in it perhaps?

[roofer]

When it's warm, if you hold the revs at a constant 3k, what can you hear ?

And the sensors on BMW's are notoriously st.

[helix402]

29F3 - Fuel low-pressure sensor, electric-sensor is faulty, needs changing
30C1 - Engine oil pressure control, static-has any one tested the oil pressure?
2A99 - Crankshaft - exhaust camshaft, reference-needs diagnosing, is cam timing ok?
30DA - Nitrogen-oxide sensor, signal-most N43s have this fault stored, usually cured once the other faults are fixed by an Italian decoke. This applies to all the NOX faults, very rarely the sensor is faulty
2AF4 - Nitrogen-oxide sensor, electric
2AF2 - Nitrogen-oxide sensor, lambda linear
2AF6 - Nitrogen-oxide sensor, lambda binary
2AF9 - Nitrogen-oxide sensor, NOX signal, coast-mode checked

Worth changing the timing chain tensioner and checking the cam timing and oil pressure.

[northwest monkey]

roofer said:

When it's warm, if you hold the revs at a constant 3k, what can you hear ?

And the sensors on BMW's are notoriously st.

I'll give this a go tomorrow - pretty sure just the sound of the engine rather than any knocking. I'm not going to disagree about the sensors!

[northwest monkey]

helix402 said:

29F3 - Fuel low-pressure sensor, electric-sensor is faulty, needs changing
30C1 - Engine oil pressure control, static-has any one tested the oil pressure?
2A99 - Crankshaft - exhaust camshaft, reference-needs diagnosing, is cam timing ok?
30DA - Nitrogen-oxide sensor, signal-most N43s have this fault stored, usually cured once the other faults are fixed by an Italian decoke. This applies to all the NOX faults, very rarely the sensor is faulty
2AF4 - Nitrogen-oxide sensor, electric
2AF2 - Nitrogen-oxide sensor, lambda linear
2AF6 - Nitrogen-oxide sensor, lambda binary
2AF9 - Nitrogen-oxide sensor, NOX signal, coast-mode checked

Worth changing the timing chain tensioner and checking the cam timing and oil pressure.

I've read a bit about the chain tensioner & it seems a (relatively) straightforward job - easy enough for a DIY?

The oil pressure and cam timing I'm guessing is a garage job. Any idea on costs for this? Mainly to make sure I don't get fleeced - I've already spoken to a garage who reckons the tensioner is a 5-hour job whereas a lad on another forum says about 30 minutes...

If the timing was out, could this have an impact on the oil pressure? What I'm getting at is, are there 2 separate problems (1 being rumbling and the other being oil pressure) or could one thing be causing the other? I'm not a mechanic, but logic says if the timing is out (because of a slipped/stretched chain or otherwise) then if things aren't doing what they should be doing at the right time then this could lead to oil being in places it shouldn't be at the wrong time (if that makes sense).

You wouldn't by any chance happen to be anywhere in the North would you?

[helix402]

Tensioner change is 30mins. Checking timing is a longer process. Afraid I'm not in the North, escaped many years ago!

[northwest monkey]

roofer said:

When it's warm, if you hold the revs at a constant 3k, what can you hear ?

The same noise but louder. I can't work out if it's coming from the top or the bottom.

Seriously annoying - I love cars and hate them at the same time

[roofer]

Mains will rumble, ends will clatter.

[northwest monkey]

It's sort of a clattery rumble

I know these 2.0 engines aren't the ultimate in refinement, however this one is doing a good impression of a diesel at the moment.

[roofer]

If it is low on oil pressure, I wonder if the lifters are having trouble filling.

[northwest monkey]

roofer said:

If it is low on oil pressure, I wonder if the lifters are having trouble filling.

Could that be a cause or an effect of the low oil pressure?

[roofer]

Effect.

[northwest monkey]

Woohoo.

Well I'm taking it to a BMW specialist on Friday who's going to have a good look at it & that's when the fun begins I suppose...

From speaking to the bloke on the phone, it's sounding like at best it needs a rebuild.

[iSore]

Christ, the N43 of death. It's done well to get to 106'000 miles. A bottom end rebuild will probably be needed but at least the crank is the same as the older N42/N46 unit - for some reason these don't often have crank problems even though it's the same part. A good used crank, new shells and bolts, a chain and guide rail kit and a new oil pump. Also ask the garage to closely inspect the oil pick up pipe as these can fracture, causing the pump to pick up air as well as oil.

These four cylinder N engines are fking rubbish, they really are. N for nightmare.

[helix402]

Did you know the N43 etc were made near Birmingham?

[iSore]

Yep. Derived for the unlovely N42/46, destined for a Rover product that never happened.